Cryptographers arise!

Cryptography is a strange field, in that it’s both concerned with keeping secrets, but also has a long history of being kept secret, as well. There are famous names from the early days, from Caesar (Julius, that is) to Vigenère, to more recent names like Diffie, Hellman[1], Rivest, Shamir and Adleman. The trend even more recently has been away from naming cryptographic protocols after their creators, and more to snappy names like Blowfish or less snappy descriptions such as “ECC”. Although I’m not generally a fan of glorifying individual talent over collective work, this feels like a bit of a pity in some ways.

In fact, over the past 80 years or so, more effort has been probably put into keeping the work of teams in cryptanalysis – the study of breaking cryptography – secret, though there are some famous names from the past like Al-Kindi, Phelippes (or “Phillips), Rejewski, Turing, Tiltman, Knox and Briggs[2].

Cryptography is difficult. Actually, let me rephrase that: cryptography is easy to do badly, and difficult to do well. “Anybody can design a cipher that they can’t break”, goes an old dictum, with the second half of the sentence, “and somebody else can easily break”, being generally left unsaid. Creation of cryptographic primitives requires significant of knowledge of mathematics – some branches of which are well within the grasp of an average high-school student, and some of which are considerably more arcane. Putting those primitives together in ways that allow you to create interesting protocols for use in the real world doesn’t necessarily require that you understand the full depth of the mathematics of the primitives that you’re using[3], but does require a good grounding in how they should be used, and how they should not be used. Even then, a wise protocol designer, like a wise cryptographer[4], always gets colleagues and others to review his or her work. This is one of the reasons that it’s so important that cryptography should be in the public domain, and preferably fully open source.

Why am I writing about this? Well, partly because I think that, on the whole, the work of cryptographers is undervalued. The work they do is not only very tricky, but also vital. We need cryptographers and cryptanalysts to be working in the public realm, designing new algorithms and breaking old (and, I suppose) new ones. We should be recognising and celebrating their work. Mathematics is not standing still, and, as I wrote recently, quantum computing is threatening to chip away at our privacy and secrecy. The other reasons that I’m writing about this is because I think we should be proud of our history and heritage, inspired to work on important problems, and to inspire those around us to work on them, too.

Oh, and if you’re interested in the t-shirt, drop me a line or put something in the comments.

1 – I’m good at spelling, really I am, but I need to check the number of ells and ens in his name every single time.

2 – I know that is heavily Bletchley-centric: it’s an area of history in which I’m particularly interested. Bletchley was also an important training ground for some very important women in security – something of which we have maybe lost sight.

3 – good thing, too, as I’m not a mathematician, but I have designed the odd protocol here and there.

4 – that is, any cryptographer who recognises the truth of the dictum I quote above.